Juliette Lewis plays the mentally challenged daughter of a wealthy San Francisco couple (Diane Keaton and Tom Skerritt) who decides to strike out on her own; she becomes involved with a similarly impaired boy (Giovanni Ribisi) she meets at a vocational school, and things come to a crisis at a wedding reception for one of her sisters. Part of the problem with this comedy-drama, which oscillates bewilderingly between contrived and insightful, mechanical and sincere, clumsy and graceful, is that the hokey style of filmmaking often seems aimed at the mentally challenged; but sometimes it’s affecting in spite of everything. Lewis is resourceful but uneven, if only because her character’s intelligence seems to vary considerably from one scene to the next. Garry Marshall directed from a script he wrote with Bob Brunner, and has an especially awkward time handling flashbacks. Thankfully, these are few and brief. (JR)